Air Bubble Tubs and Water Temp

I have read afew forum posts discussing the effects of physics on water temp for air bubble tubs. As we plan our master bath remodel I am leaning toward a drop in air bubble tub but do have a concern aboiut water temp. Nothing worse than a tepid tub of water when soaking an aching back or neck. I see where many have low wattage heaters but not convinced they have enough wattage to heat much.

So thats the question.. does anyone have positive experiences with an air bubble tub that has some form of a heating system (other than having an endless supply of hot water for continuous refills) that actually works? Appreciate any feedback! Thx

DonL.. that was what I meant. Not trying to heat the water but want to maintain the temp even when air bubbles are going through. Seeking user feedback on tubs that actually do a good job of this. Some hot refresh isn't an issue but rapid cooling is. Most claim to have some form of in line heater or air heater but not much is specified in terms of wattage or how well they do their job. Other I have seen offer things such as "hyrdo Fusion" that apprently recirculate and reheat the water to maintain original temp. Question I have is do these things work!

The act of compressing and pumping the air heats it. Try using a pump to add air to a bike tire and you'll see what I mean. But, most of them require the inlet air to be at least 70-degrees so it's adequate once compressed, so where you draw that air can make a difference. I have an air tub by Jason International. The air turbine is on a timer, and with one 'shot' it runs for 20-minutes. The water temp does drop some during that time, but I start it out a little hotter than I like and it's fine at the end. Those tubs that combine both air and water pumps typically also have in-line heaters. On mine, it's just air, and I don't miss having a heater. Throwing in a water circulator and heater negates some of the benefits of an air tub in that it will limit what you can use in the water, and the cleaning regimen will be MUCH more tedious and intolerable of slack. With just an air tub, it blow dries the internal passages when finished. Try that when water is involved, and you'll ruin the pump, so that stagnant water sits there between uses and things can and will grow.

An air tube does not "compress" the air, it just moves it through the water. When air mixes with water, the "hottest" water is released as steam which is why the tub cools off. Without water circulation, there is no way to install a "remote" heater. I am not sure how effective a "blow dryer" would be for reheating the water.

Thx for returning my thoughts to one of the reasons why I dislike whirpools... taking water out of the tub and circulating them around. Obviously an in line heater such as that is doing same "trick". As long as the water isn't cooled super quickly I should be fine. I do not normally spend more than 15 minutes soaking at a time.

That said my 1992 vintage house does not have anti scald devices and I am able to enjoy really hot water. When bathroom remodel goes in I will need to be careful with new valves to ensure I can deliver hotter water than say 104 degrees. Another topic though. I am still leaning toward a BW 75 gallon water heater though AO SMith Vertex units are under consideration even with higher price tag as they seem capable of delivering up to 3 gpm of hot water endlessly. Having hot water make up in event air bubbles too rapidly cool the water might be a good idea.

Based on your post I think I will abandon to kepe it warm heater idea. There are 2 places that sell Jason Intl about 2 hours form me but we go there fairly often due to mother in law's passing and tending to her home so it may give me a chance to price them out and see them. Am having a difficult time finding places that actually have much on disply to see. Thx for the post! It helps.

I have a thermostatic filler valve...it has a safety stop at (I think) 105, but you can press a button and override that. I do not find I need to go above the safety stop. An anti-scald valve is supposed to be adjusted (at the time of install) to limit the max temp. This is somewhat problematic, since it is only adjusting the hot/cold balance, and the cold temp can vary considerably winter/summer. The thermostatic valve seems to maintain, regardless. It is especially useful as you start to drain the WH, since it will keep adding more hot to maintain the set temp, while a standard valve just maintains the balance between the hot and cold, disregarding the fact the hot may be cooling. I've got a 60g tank, and I"ve never run out of hot, but my use pattern may differ from yours.

I have a thermostatic filler valve...it has a safety stop at (I think) 105, but you can press a button and override that. I do not find I need to go above the safety stop. An anti-scald valve is supposed to be adjusted (at the time of install) to limit the max temp. This is somewhat problematic, since it is only adjusting the hot/cold balance, and the cold temp can vary considerably winter/summer. The thermostatic valve seems to maintain, regardless. It is especially useful as you start to drain the WH, since it will keep adding more hot to maintain the set temp, while a standard valve just maintains the balance between the hot and cold, disregarding the fact the hot may be cooling. I've got a 60g tank, and I"ve never run out of hot, but my use pattern may differ from yours.

Click to expand...

jad,

which filler valve are you using? I like the faact it can be overridden if needed. I know some who have had issues with tankless water heaters can trace some of their issues to setting the water heater temp too high causing flow rate issues, etc. I have not been having any issues with my now aging 50 gallon WH and current soaker tub but then the inlet cold water is quite warm. I typically fill hot wide open and then cool as needed. The anti scald features will take some getting used to and having ability to do what yours does will be nice! Thx again for the info.. my contractor will love it

Anti-scald will have nothing to do with restricting your ability to get hot water out - it should be set to limit the max temp of 120-degrees, but that's an internal mechanical stop you can adjust (typically at installation). The issue with anti-scald is multi-faceted: it provides a means to limit max temp (user settable), AND, it prevents a radical spike in temperature should there be a hiccup in the supply (such as when someone may flush a toilet or something to change the pressure on one of the supply lines - it adjusts the temp momentarily to compensate - maintaining the balance you've set on hot/cold). So, you should not find any real functional differences.

My situation is somewhat uncommon - the wet wall has an air duct behind it, making it really tough to service or install something, plus, it also has a pocket door there as well! So, I ended up with a surface mounted tub filler/valve from Grohe. IOW, all of the valve is external, only the supply lines come out of the wall and directly into the valve. But, most all manufacturers make a decent thermostatic controlled valve. Look at the Delta R10000 rough-in valve with the 1700-series trim. That rough-in valve can take any of three different styles of cartridges, giving you a choice of function, so you're not stuck with one, should you later change your mind. I've had good luck with the Grohe, and it should work for you as well. I was exposed to how well they worked in a London hotel...marginal supply lines, pressure bouncing all around, constant temperature out. Over that week, I only needed to turn the volume control on/off, never had to touch the temp setting.

Anti-scald will have nothing to do with restricting your ability to get hot water out - it should be set to limit the max temp of 120-degrees, but that's an internal mechanical stop you can adjust (typically at installation). The issue with anti-scald is multi-faceted: it provides a means to limit max temp (user settable), AND, it prevents a radical spike in temperature should there be a hiccup in the supply (such as when someone may flush a toilet or something to change the pressure on one of the supply lines - it adjusts the temp momentarily to compensate - maintaining the balance you've set on hot/cold). So, you should not find any real functional differences.

My situation is somewhat uncommon - the wet wall has an air duct behind it, making it really tough to service or install something, plus, it also has a pocket door there as well! So, I ended up with a surface mounted tub filler/valve from Grohe. IOW, all of the valve is external, only the supply lines come out of the wall and directly into the valve. But, most all manufacturers make a decent thermostatic controlled valve. Look at the Delta R10000 rough-in valve with the 1700-series trim. That rough-in valve can take any of three different styles of cartridges, giving you a choice of function, so you're not stuck with one, should you later change your mind. I've had good luck with the Grohe, and it should work for you as well. I was exposed to how well they worked in a London hotel...marginal supply lines, pressure bouncing all around, constant temperature out. Over that week, I only needed to turn the volume control on/off, never had to touch the temp setting.

Click to expand...

JAD,

Thx.. this will give me something to look into. Am waiting on initial quotes for both bathrooms. Luckily this time around I don't have to do it multiple times as I already know and trust the contractor. My bathroom has some size limitations.. it isn't small but just isn't large enough to do everything easily. I currently have a knee wall between the garden tub and toilet and we will probably maintain that wall (meaning anew one) in the remodel. My tub fixtures may well come out of the wall versus top mounting on tub ( said MAY) so what you are describing may work well.

The anti scald part I understand the logic and can see the benefit though like any thing I can see liability as well. If I had a choice I would forego it.. one of those don't have it now things and keep it simple. That said once remodels are done I'll have that feature and this information will help! This is starting to remind me of our kitchen remodel. So many things to question and learn along the way! But kitchen overall came out nearly perfect and we have been very happy and thus the questions and help offered are always appreciated!